BIOLOGICAL STUDIES OF THE GREEN CLOVER WORM 15 



shows the periods of occurrence of the adult and immature stages, as 

 found from April to October, inclusive. Adults in abundance were 

 noted about the first of April and remained fairly numerous until 

 the middle of that month. By April 27 young larvse of the first 

 generation appeared, and larvae were found abundantly distributed 

 over the fields throughout the month of May. In the interval the 

 moths nearly disappeared, and only a few battered individuals could 

 be found until about the middle of June, when freshly emerged moths 

 began to appear in great numbers. During the middle and last of 

 June young larvse of the second generation became plentiful in the 

 field and remained very numerous until the second week in July, by 

 which time they had reached full growth and were pupating. By 

 July 18 newly emerged moths from this second generation began 

 to appear, and by July 24 they were found in great numbers in the 

 field. The third generation of larvse, resulting from eggs laid by 

 these moths, were present in the field in abundance by the second 

 week in August, and adults, although present in the field, were 

 greatly diminished in numbers. During this time the weather was 

 warm and the caterpillars were maturing rapidly. By August 22 

 practically all of these had pupated and newly emerged moths were 

 becoming numerous. Young larvse of the fourth generaton were 

 found about the 1st of September, but by the 12th only a few battered 

 moths were present. Larvse continued abundant throughout the 

 remainder of the month. In October a few freshly emerged adults 

 were collected. 



According to certain authors (4, 10), the number of generations is 

 fewer farther north, decreasing to three and even two per annum. 



HIBERNATION 



Observations indicate that hibernation takes place in both the 

 pupa and adult stages. Although repeated attempts to carry the 

 moths through the winter in cages failed, yet in the field at Nashville, 

 Tenn., they were found numerous during October and part of Novem- 

 ber, and again during the first warm days of February. Philip 

 Luginbill observed five moths flying in a woodshed at Columbia, 

 S. C, on January 5. Chittenden (2) observed that "About the city 

 of Washington this moth is one of our latest as well as earliest species, 

 individuals occurring commonly in the writer's experience about the 

 Department of Agriculture buildings throughout November, as 

 late as the first week in December, and as early as March 10." Riley 

 (0) reported a large number of these moths transmitted to Washing- 

 ton during the winter by correspondents who confused it with moths 

 of the cotton leafworm (Aletia) Alabama argillacea Hbn. 



As stated in the discussion of the pupal stage, pupse formed late in 

 the fall at Knoxville, Tenn., failed to produce adults until brought 

 into the heated laboratory. If left in the field, they might have passed 

 the winter in this stage. One pupa in an outdoor cage remained alive 

 as late as December 22. In this connection it might be mentioned 

 that Riley (9) stated that pupa; wore found in Missouri throughout 

 the winter. . 



